1. Field of the Invention
A. The invention generally relates to a method of treating elastomeric articles made from extensible hydrocarbon materials in order to reduce their surface friction characteristics and improve their chemical inertness.
B. The invention has particular utility for medical articles, such as surgeons' gloves, that require sliding contact with the surface of the elastomer.
2. Description of the Prior Art
Extensible articles made from hydrocarbon elastomers are now in wide use, particularly in the medical field. For example, medical articles such as surgeons' gloves, catheters, condoms, endoscopic tubes, contraceptives such as intrauterine devices, etc., can be made from a latex rubber or other hydrocarbon elastomeric materials. For medical, surgical and other uses, it is frequently required that such flexible articles be disposed in intimate contact with tissue and/or be used in the presence of blood. In some cases, extension of the article may be concomitant with contact with tissue, as is the case, for example, with the inflated segment of a tracheal tube. In many such medical applications, high friction between the extensible or extended article and the adjacent tissue deleteriously affects the physical properties of the article itself and/or creates a source of irritation for the tissue.
While this invention is not limited to any particular extensible article, it will be illustrated with reference to common, but yet relatively complex in shape, articles such as surgeons' gloves.
Prior to donning a pair of conventional gloves, common practice requires that a lubricating agent such as powder be sprayed inside the gloves, or that the surgeon powder his hands. Also in some manufacturing processes a lubricating powder is generously used on the gloves to facilitate their removal from molds or forms. The same powder also subsequently serves as the desired lubricating agent.
It is now widely recognized that the presence of any lubricating powder on surgeons gloves may lead to potential medical complications, as more fully described in an article entitled THE GLOVE STARCH PERITONITIS SYNDROME by Ignatius et al, published in the Annales of Surgery, March, 1972, Vol. 175, No. 3, pages 388-397.
The potential medical complications are generally attributed to the lubricating powder's fine particles eliciting local inflammatory responses in adjoining tissue. Recently the U.S. Food and Drug Administration issued guidelines for surgical practice which encourage the surgeon to wipe his gloved hands thoroughly with a moist sponge prior to performing surgery in order to remove whatever powder may exist on th gloves' outer surfaces. Even if this recommended cleansing treatment were to remove most of the lubricating powder from the gloves' exterior surfaces, a tear in the glove might allow the transfer of powder from the glove's inner surfaces into an adjoining operative site, where the presence of powder might cause tissue inflamation. In addition to the patient's response to the powder, the wearer himself may suffer a dermatologial allergy.
Also, since fine particles of lubricating powder resist being completely washed away from the gloves' surfaces, they maintain the slipperiness of such surfaces. This apparently unavoidable residual lubricating effect of the powder, especially in the presence of blood, hinders the precise manipulation of surgical instruments and tends to reduce the tactile sensation between the surgeon's fingers and such instruments.
Another glove lubricating process is described in U.S. Pat. No. 3,626,517 which involves the development of a lubricating coating on the glove's inside surface. During the donning of a surgeon's glove, its aperture must be stretched substantially in order to allow penetration of the surgeon's hand inside the glove. The aforesaid lubricating coating could easily fracture during distension of the glove, since the coating's stress elongation characteristics are normally substantially less than the stress elongation characteristics of the glove. The fractured coating and its debris can become a source of tissue irritation.
Other extensible elastomeric articles such as catheters are covered with a jelly, instead of a powder or a coating lubricant, to facilitate their insertion through a luminal orifice of a human body. Catheters are commonly used for relief of bladder contents and can reside in place in the body for more than a few hours. In the body, the jelly lubricant coating gradually loses its lubricating properties leading to a gradual irritating interaction between the catheter and the adjacent tissue. Such irritation may reduce the resistance of the body's luminal orifice to the migration of infectious bacteria through the orifice.
Accordingly, it is a broad object of this invention to provide a method for treating extensible elastomeric articles especially those that are suitable for medical use and are required to have low friction surface characteristics.